Posted By J Knight The laptop itself is low voltage, typically 12v, so shouldn't require formal testing. The transformer and mains cable upstream of this will need testing to a frequency detremined by the usual factors; more than once a year I would say, certainly fairly frequent visual inspections. Of course, this assumes that the laptop has an external transformer; most of them do, if the transformer is built in then test & inspect more frequently; as usual the inspection is the more important, John